Recycling method for scrap silicon

A method of recycling scrap silicon produced during the manufacture of a silicon product from a silicon ingot comprising:

• selecting scrap silicon for which the expected sale price of a resultin silicon product exceeds the total of the purchase price and the refining cost of the scrap silicon,
• recovering the selected scrap silicon by purchasing lumps of scrap silicon produced during the manufacture of a silicon product from a silicon ingot, measuring the electrical resistivity of the purchased lumps of scrap silicon, and selecting from the purchased lumps of scrap silicon, based on the measured electrical resistivity, lumps of n-type scrap silicon which are each made of the selected scrap silicon and which each contain as a dopant only the same specific impurity element;
• and
• refining the recovered scrap silicon to reduce the level of the specific impurity element in the recovered scrap silicon and obtain a silicon product which can be sold as a silicon material by crushing the selected lumps of scrap silicon, placing the crushed silicon into a vacuum vessel, irradiating the crushed silicon which was placed into the vacuum vessel with an electron beam to melt it and vaporize at least a portion of the specific impurity element, and solidifying the resulting molten silicon.